Grommet

Abstract

A grommet is provided which can reduce an insertion load without decreasing a disengagement load of an inserting member. The inserting member, having a leg portion and a head portion formed by increasing the diameter of a tip end of the leg portion, is inserted from one end side of a body portion of the grommet into an insertion hole and attached to an inserted member with the grommet interposed. On the one end side from a groove portion formed in an outer circumferential surface of the body portion, a diameter of the insertion hole is equal to or larger than a diameter of the head portion. On the other end side from the groove portion, the grommet has a small diameter portion in which a diameter of the insertion hole is smaller than the diameter of the head portion and is equal to or larger than a diameter of the leg portion.

1. A grommet which engages with a peripheral portion of an opening formed in an inserted member and is interposed between an inserting member inserted into said opening and said inserted member to attach said inserting member to said inserted member, comprising
 a tubular body portion having an insertion hole into which said inserting member is inserted, 
 said body portion including a first flange portion shaped in a collar protruding radially outward of said body portion at one end and a second flange portion shaped in a collar protruding radially outward of said body portion at the other end which is opposite to said one end, wherein 
 in an outer circumferential surface of said body portion, a groove portion is formed such that a part of said outer circumferential surface is depressed in an elongated shape along a circumferential direction of said outer circumferential surface between said first flange portion and said second flange portion in an axial direction, said groove portion engaging with said peripheral portion to attach said grommet to said inserted member, 
 said first flange portion has a thrust surface on a side thereof, 
 said second flange portion has another thrust surface on a side thereof such that said another thrust surface faces said thrust surface, 
 said inserting member, having a leg portion and a head portion formed by increasing a diameter of a tip end of said leg portion, is inserted from said one end of said body portion into said insertion hole and is attached to said inserted member, 
 on said one end, a diameter of said insertion hole is equal to or larger than a diameter of said head portion, and 
 on said other end, said grommet has a small diameter portion in which a diameter of said insertion hole is smaller than the diameter of said head portion and is equal to or larger than a diameter of said leg portion, 
 when said inserting member is inserted from said one end into said insertion hole, said inserting member abuts on an inner wall surface of said insertion hole, said thrust surface comes into surface contact with said inserted member, and said second flange portion is deformed such that the diameter of said insertion hole is increased, and 
 when said inserting member attempts to be disengaged from said grommet, said inserting member abuts on said other end, said another thrust surface comes into surface contact with said inserted member, and said second flange portion is deformed such that the diameter of said insertion hole is reduced. 
 
     
     
       2. The grommet according to  claim 1 , wherein
 said grommet has a reduced diameter portion in which a diameter of said insertion hole is gradually reduced from said one end toward the other end, and 
 said insertion hole is formed to have a diameter equal to the diameter of said head portion, at said reduced diameter portion.